This invention relates to solar cells, particularly to a silicon carbide coverplate for a silicon solar cell.
The use of photovoltaic devices, commonly known as solar cells, to convert light energy to electrical energy is well known. The efficiency of a solar cell is directly related to the amount of useful light which is absorbed by the solar cell. Only a portion of the light striking the top surface of a solar cell is useful to the cell. Another portion of the light striking the cell is nonuseful, i.e., the light has wavelengths outside the range useful to the cell; and yet another portion of light is reflected by the solar cell. To reduce the problem of light reflection, solar cells employ an antireflective coating positioned on the surface of the solar cell through which light enters.
The antireflection coating improves the absorption of light in the useful wavelength range by reducing reflection of such light. The coating also absorbs and reradiates or reflects light in the nonuseful wavelength range.
In space applications, where reliability in a hostile environment and over extended time periods is required, a cover slide, generally quartz, is placed over the antireflective coating to shield the solar cell from harmful radiation. The use of quartz has, however, created problems since quartz will strongly absorb high intensity radiation in the 9 to 11 micron range, causing degradation in the solar cell.
Accordingly, it is an object of the present invention to provide a replacement for the quartz cover slide used heretofore in solar cells.
Other objects and advantages of the invention will become apparent upon consideration of the following detailed description.